Stability control systems currently exist in various forms such as electronic stability control systems (ESC), yaw stability control systems (YSC), and roll stability control systems (RSC). Such systems are used to maintain controlled and stable vehicle operations for improved vehicle and occupant safety. Stability control systems are often used to maintain vehicle traction and to prevent or mitigate a rollover event.
Current stability control systems are well adapted for ride comfort and road handling. The sensing systems for detecting rollover events rely on yaw and roll rate sensors and accelerometers to determine if the vehicle has exceeded the limits of lateral stability. These systems work well for rollover scenarios that do not involve significant lateral forces, referred to as untripped rollover events. However, tripped rollover events, such as hitting a curb while sliding laterally, generate significant lateral forces which can move an occupant outboard, often before the vehicle has experienced enough roll angle to be detected by the roll and yaw sensors. Thus, conventional stability control systems are limited in their ability to mitigate and prevent tripped rollover events.
Stability control systems typically mitigate rollover events by aggressively increasing the brake fluid pressure to quickly brake one or more tires. The braking counteracts the forces experienced during such an event, thereby, stabilizing the vehicle. When tire pressure is low, however, such RSC system interventions can be less effective and even lead to tire-debeading. The term “tire-debeading” refers to the separation of the bead wire from a tire and thus the breakdown of that tire. Debeading of a tire can result in rim or wheel contact with a road surface and resultant vehicle instability.
Thus, there exists a need for an improved stability control system, which overcomes the limitations of current stability control systems to detect tripped rollover events. There also exists a need for an improved stability control system that accounts for low tire pressure situations.